Define a bootstrap sandbox policy for renderer processes and enable it.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 890c3909dcb984dfadc7191765722edf3166df40..7501fd686776735b53c9ac3e3931edcc022a5775 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -169,6 +169,10 @@
 #include "ui/gfx/win/dpi.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "content/public/common/sandbox_type_mac.h"
+#endif
+
 #if defined(ENABLE_WEBRTC)
 #include "content/browser/media/webrtc_internals.h"
 #include "content/browser/renderer_host/media/media_stream_track_metrics_host.h"
@@ -327,6 +331,11 @@ class RendererSandboxedProcessLauncherDelegate
   virtual int GetIpcFd() OVERRIDE {
     return ipc_fd_;
   }
+#if defined(OS_MACOSX)
+  virtual SandboxType GetSandboxType() OVERRIDE {
+    return SANDBOX_TYPE_RENDERER;
+  }
+#endif
 #endif  // OS_WIN
 
  private: